A planar shape characteristic measuring apparatus, and a planar shape characteristic measuring method, which can precisely and efficiently measure the characteristics relating to a surface shape of the measured surface of a disk such as a data recording surface of an optical disk including a laser Doppler speed meter which detects a perpendicular direction speed of a measured surface of a rotating disk; a tilt angle calculating unit which calculates a tilt angle in the rotational direction of an optical disk at each measuring position to a reference surface based on a linear speed at each measuring position detected by the laser Doppler speed meter and the detected perpendicular direction speed; a displacement calculating unit which calculates a perpendicular direction displacement of the optical disk at each measuring position; an acceleration calculating unit which calculates a perpendicular direction acceleration; and a tracking error calculating unit which calculates a tracking error which is predicted to occur in a focus servo system.
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